Dry-drowning, or who the fuck builds a megacity on a lake:

When the conquistadors arrived at Tenochtitlan, they found a city of 400,000 at peace with its environment. The neighborhoods were situated on floating islands surrounded by sustainable agriculture and large canals. Naturally, upon conquering the city, the Spanish set about building over this with their own designs, draining the lake to prevent pesky floods. As the city expanded through the centuries, it drained more and more of the lake until it was eventually entirely paved and built over, choosing instead to pump water from the underground aquafers that previously supplied the lake. When even more water was required, Mexico created a true feat of engineering, pumping water from the closest water source 2,700 meters up a mountain before gravity feeding it 100km down into the city. As it stands now, these supplies are entirely insufficient for the capital and its rapid urbanization. The rich neighborhoods closest to the pipeline enjoy constant clean water and enough pressure to water their golf courses, while boroughs on the opposite side of the city go up to 6 weeks without running water and what does come through is often contaminated and toxic. The use of underground aquafers to supplement water supply has also caused the city to begin sinking at an alarming rate. The unregulated paving and urbanization of the area has blocked the pathways through which rainfall would naturally regenerate these sources, causing them to be depleted at unsustainable rates. This rapid sinking of the city destroys and degrades water infrastructure, creating a potentially catastrophic loop as more water is drawn from the aquafers to supplement the water lost by the consequences of drawing from the aquafers.

Despite the immense amount of pipe infrastructure and complex engineering involved in transporting water, 40% of it never makes it to taps, instead being lost to leakages in the system. Each year this amounts to more water than is consumed in Guadalajara and Monterrey combined. Of this 40%, 88% is lost through the connections to homes, as many of these connections are poorly planned and many households cannot afford to pay plumbers. The mayor of Mexico City has recently implemented 75 brigades dedicated to finding and fixing leaks, while Sacmex has hired an additional 315 staff members to fix reported damage. On top of that, we will commit to a further 100 brigades to fix the more than 150 reported daily leaks. Trenchless pipe repair technology will be employed to save millions of dollars and prevent congestion caused by digging up streets and walkways. To aid in accurately measuring and discovering leakages, the use of water meters will be extended further into the city, as well as dedicated teams to read and keep track of them. Much of the degradation of water connections comes from pipes getting damaged during earthquakes or by the uneven sinking of the city. In order to remedy this, pipe infrastructure will be constructed along the entire length of the subway system and in several above ground sections. This should help protect the pipelines from the dangers of geological movement and in the event leakage does occur, accessing them will be far easier as they’re open air. Using the subway will also allow water to reach further into Mexico City’s sprawling suburbs, improving overall access. The construction of alternative pipe routes, as well as more teams to maintain them is estimated to cost approximately $350 million, part of which will be funded by Sacmex. An extra $100 million a year will be committed to the water management departments budget in order to fix and maintain the underfunded system.

The Iztapalapa borough is one of the hardest hit areas of the city by water shortages, sometimes going six weeks without access to running water. The already impoverished people of this neighborhood spend huge chunks of their pay on access to water trucks, a once temporary measure for times of crises, now a permanent fixture in life here. Often the women spend days waiting for water deliveries, forcing them to stay in the home and preventing them from getting jobs to support their families. Furthermore, the water provided in this area is rarely clean and contains toxins and metals that may cause severe health issues that these people cannot afford to treat. A solution to this crisis is Lago de Chalco, an area previously drained entirely that has slowly begun filling with water again. For $275 million, the lake will be dredged to eight meters and a state-of-the-art water treatment facility will be built, allowing water to be drawn from the lake without disturbing the underground aquafers. Once this source has been connected to the existing pipelines, it will provide reliable running water for an estimated 1.5 million people in the area, allowing many women to return to work and increasing the local water quality, boosting income and productivity while reducing expenses and health issues.

One of the largest flaws in the water supply system of Mexico City is the complete lack of utilization of rain and stormwater in a region with more rainy days than London. For six months a year the region receives regular deluges, causing large-scale flooding in the very regions that struggle to obtain running water, a clear failure on our part. Furthermore, the stormwater and sewerage systems drain into the same canals, wasting easily recyclable water and meaning that floods caused by storm surges often contain raw sewage, a major public health risk. One of the ways in which rainwater is being utilized is La Quebradora Hydraulic Park also in Itzapalapa, a four-hectare sustainable rainwater capture and treatment area that doubles as a public space. The facility features a water treatment plant, two artificial wetlands, solar panels for power, a cultural center, public recreation areas and access to clean water amenities. Built on porous volcanic rock, the project allows rain to easily filter through the subsoil and into the overexploited aquafers a process that is interrupted by the endless sea of concrete that is Mexico City. Furthermore, stormwater drains that would typically flood the neighborhood will be redirected to the facility, where it will be treated and either pumped into the aquafer, used for irrigation of the public space or turned into potable water for the community. Its estimated that this project will infiltrate 68 million liters of water into the subsoil each year, replenishing the overexploited aquafers, preventing the sinking of the city and providing a community space for one of the city’s poorest boroughs. This project cost an estimated $20 million and three more like it will be built in communities identified as having porous soil and significant rainwater runoff.

Rainwater will also be utilized in a decentralized and city-wide manner through the construction of household level rainwater harvesting technology. The system uses a device called a tlaloque, which fills up during the first few minutes of rain. This first water is very dirty as the rain washes the dirt off the roof. Once the tlaloque is full, a ball floats up and blocks it, allowing the rest of the water to flow into a cistern. This reduces up to 75% of the water contamination before any further filtering or chlorine treatment. The water from the tlaloque can still be used for purposes such as watering plants or washing floors or cars. The water that flows into the cistern can be used right away for most household purposes but must be cleaned further to be safe enough to drink. These systems are estimated to provided 60-75% of household needs. Currently, installation and operations training is done by multiple not-for-profit organizations who plan to construct 100,000 of these systems over the next six years. At an average of $5000 per system, the Mexican Government will match this commitment for a total cost of $500 million over the next 6 years. These will be for primarily low-income neighborhoods, while richer areas of the city will be encouraged to finance their own systems through the potential savings on water bills and more freedom from the water restrictions imposed on tap water. Furthermore, new private developments will be mandated to install rainwater harvesting systems in their housing designs to ensure the city is growing in a sustainable manner.

Water recycling, or lack thereof, has been a persistent problem in Mexico City. As golf courses guzzle drinkable water, millions of gallons of easily treatable water are pumped out of the city through flood management and drainage pipes. In recent years, this has been addressed with the construction of the world’s largest water treatment facility, which treats 56% of Mexico City’s wastewater. However, much of this water is used in agricultural irrigation outside the city, while many neighborhoods continue to waste and not recycle fresh water. In order to improve efficiency of water usage, boroughs that enjoy relatively uninterrupted access to city water will have their water subsidies, already substantially higher than anywhere else in the country, phased out over a period of five years. This will prevent any sudden shocks to household spending, while encouraging water conservation and recouping some of the costs of these new programs. Furthermore, the many golf courses in the Mexico City watershed area will be required to irrigate their courses with recycled water, as they require enormous amounts of upkeep. In order to permanently shift the culture around water usage in all facets of society, education campaigns will be introduced country-wide in schools, universities, workplaces and children’s cartoons to encourage conservation, recycling and responsibility around water security.

While these policies are far from comprehensive, they are a necessary step for providing our people with access to a basic human right and achieving water security in the heart of our nation.